Miryam Ciotola

CONTEXT: The metabolic syndrome has been identified as a target for dietary therapies to reduce risk of cardiovascular disease; however, the role of diet in the etiology of the metabolic syndrome is poorly understood. OBJECTIVE: To assess the effect of a Mediterranean-style diet on endothelial function and vascular inflammatory markers in patients with the metabolic syndrome. DESIGN, SETTING, AND PATIENTS: Randomized, single-blind trial conducted from June 2001 to January 2004 at a university hospital in Italy among 180 patients (99 men and 81 women) with the metabolic syndrome, as defined by the Adult Treatment Panel III. INTERVENTIONS: Patients in the intervention group (n = 90) were instructed to follow a Mediterranean-style diet and received detailed advice about how to increase daily consumption of whole grains, fruits, vegetables, nuts, and olive oil; patients in the control group (n = 90) followed a prudent diet (carbohydrates, 50%-60%; proteins, 15%-20%; total fat, <30%). MAIN OUTCOME MEASURES: Nutrient intake; endothelial function score as a measure of blood pressure and platelet aggregation response to l-arginine; lipid and glucose parameters; insulin sensitivity; and circulating levels of high-sensitivity C-reactive protein (hs-CRP) and interleukins 6 (IL-6), 7 (IL-7), and 18 (IL-18). RESULTS: After 2 years, patients following the Mediterranean-style diet consumed more foods rich in monounsaturated fat, polyunsaturated fat, and fiber and had a lower ratio of omega-6 to omega-3 fatty acids. Total fruit, vegetable, and nuts intake (274 g/d), whole grain intake (103 g/d), and olive oil consumption (8 g/d) were also significantly higher in the intervention group (P<.001). The level of physical activity increased in both groups by approximately 60%, without difference between groups (P =.22). Mean (SD) body weight decreased more in patients in the intervention group (-4.0 [1.1] kg) than in those in the control group (-1.2 [0.6] kg) (P<.001). Compared with patients consuming the control diet, patients consuming the intervention diet had significantly reduced serum concentrations of hs-CRP (P =.01), IL-6 (P =.04), IL-7 (P = 0.4), and IL-18 (P = 0.3), as well as decreased insulin resistance (P<.001). Endothelial function score improved in the intervention group (mean [SD] change, +1.9 [0.6]; P<.001) but remained stable in the control group (+0.2 [0.2]; P =.33). At 2 years of follow-up, 40 patients in the intervention group still had features of the metabolic syndrome, compared with 78 patients in the control group (P<.001). CONCLUSION: A Mediterranean-style diet might be effective in reducing the prevalence of the metabolic syndrome and its associated cardiovascular risk.

BACKGROUND: Low-carbohydrate and low-fat calorie-restricted diets are recommended for weight loss in overweight and obese people with type 2 diabetes. OBJECTIVE: To compare the effects of a low-carbohydrate Mediterranean-style or a low-fat diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetes. DESIGN: Single-center, randomized trial. Randomization was computer-generated and unstratified. Allocation was concealed in sealed study folders held in a central, secure location until participants gave informed consent. Participants and investigators were aware of treatment assignment, and assessors of the primary outcome were blinded. SETTING: Teaching hospital in Naples, Italy. PATIENTS: 215 overweight people with newly diagnosed type 2 diabetes who were never treated with antihyperglycemic drugs and had hemoglobin A(1c) (HbA(1c)) levels less than 11%. INTERVENTION: Mediterranean-style diet (<50% of daily calories from carbohydrates) (n = 108) or a low-fat diet (<30% of daily calories from fat) (n = 107). MEASUREMENTS: Start of antihyperglycemic drug therapy, defined by protocol as indicated for follow-up HbA(1c) level greater than 7% (primary outcome), and changes in weight, glycemic control, and coronary risk factors (secondary outcomes). RESULTS: After 4 years, 44% of patients in the Mediterranean-style diet group and 70% in the low-fat diet group required treatment (absolute difference, -26.0 percentage points [95% CI, -31.1 to -20.1 percentage points]; hazard ratio, 0.63 [CI, 0.51 to 0.86]; hazard ratio adjusted for weight change, 0.70 [CI, 0.59 to 0.90]; P < 0.001). Participants assigned to the Mediterranean-style diet lost more weight and experienced greater improvements in some glycemic control and coronary risk measures than did those assigned to the low-fat diet. LIMITATIONS: Investigators responsible for initiating drug therapy were not blinded to treatment assignment. Dietary intake was self-reported. CONCLUSION: Compared with a low-fat diet, a low-carbohydrate, Mediterranean-style diet led to more favorable changes in glycemic control and coronary risk factors and delayed the need for antihyperglycemic drug therapy in overweight patients with newly diagnosed type 2 diabetes. PRIMARY FUNDING SOURCE: Second University of Naples.

CONTEXT: Two-hour postprandial hyperglycemia is related to chronic complications of diabetes and is currently used in the international guidelines to drive the therapy. OBJECTIVE: Our objective was to assess the size and timing of post-meal glucose peaks in the everyday life of type 2 diabetic patients and the relationship with carotid atherosclerosis. DESIGN, SETTING, AND PATIENTS: This was an observational study performed in 644 outpatients with type 2 diabetes attending diabetes clinics located in the area of the Campania County, South Italy, who provided complete home blood glucose profiles and centralized carotid intima-media thickness (CIMT) assessment. The study was conducted from 2001-2005. MAIN OUTCOME MEASURES: Incremental glucose peak (IGP) was the maximal incremental increase in blood glucose obtained at any point after the meal. CIMT was assessed by carotid sonography. RESULTS: The level of glycosylated hemoglobin and CIMT progressively increased across quintiles of IGP (P for trend = 0.01 for both). In univariate analysis, all examined glycemic parameters were significantly correlated with CIMT. IGP (r = 0.40; P = 0.006) showed the strongest correlation with CIMT, which remained significant in multiple linear regression analysis (R(2) = 0.26; P = 0.01). IGP was associated with a significant increase of CIMT in tertiles of glycosylated hemoglobin. IGP occurred within 1 h from the start of the meal in 95% of the entire diabetic population. CONCLUSION: IGPs are frequent in the everyday life of patients with type 2 diabetes, occur for most (95%) within 1 h after meal, timing of IGPs is not influenced by treatment (diet or drugs), and IGPs correlate with CIMT.